Type B insulin resistance complicated with systemic lupus erythematosus.

Type B insulin resistance is characterized by the appearance of autoantibodies to the insulin receptor. We present a 59-year-old Japanese man with type B insulin resistance complicated with systemic lupus erythematosus (SLE). A high titer of anti-insulin receptor autoantibodies was revealed when SLE was defined as active disease. Intravenous boluses of cyclophosphamide (IVCY) with oral prednisolone and cyclosporin A induced remission of SLE, and a subsequent disappearance of anti-insulin receptor autoantibodies, followed by a recovery of glucose intolerance. This is a rare and important case report showing a clear correlation between anti-insulin receptor autoantibodies of type B insulin resistance and SLE disease activity.